Support assembly in a thermal storage device

Abstract

A heat storage device, such as a hot blast stove (10), includes a regenerative checkerwork (14) of checker bricks (12) supported by a support assembly (16). According to one aspect of the invention, the support assembly (16) includes a load bearing structure (20) of refractory material and load bearing slabs of refractory material disposed on the load bearing structure (20) and configured and formed to support the checker bricks of the checkerwork (14).

Description

TECHNICAL FIELD

[0001] The present invention relates generally to a thermal storage device, in particular to a hot stove for producing hot blast. More specifically, the present invention relates to an improved support assembly designed to support the checkerwork in the thermal storage device. BACKGROUND

[0002] For blast furnace operation, a large amount of hot air, also called hot blast, is required. In large thermal storage devices, called hot stoves, cold air is preheated and injected as hot blast into the lower part of the blast furnace. Each blast furnace is usually equipped with three hot stoves, although other alternative configurations are possible.

[0003] Each hot stove is a large regenerative heat exchanger, a typical example being a cylindrical shape with a dome on top, comprising a burner section and a regenerative heat exchange section. The heat exchange section is usually composed of a refractory checker brick assembly, called checkerwork. The outer shell is a welded steel cylinder, usually 6 to 10 meters in diameter and 30 to 50 meters high. In addition, the outer shell is designed to withstand the working air pressure and is insulated in order to minimize heat losses and prevent structural damage to the outer shell due to high thermal stresses.

[0004] The operating cycle of such a hot stove essentially comprises two phases: the "on gas" and the "on air" phases.

[0005] During the "on gas" phase, a combustible gas, mainly blast furnace gas and coke oven gas, is mixed with combustion air in the burner section of the stove and burned, the hot flue gases being used to heat the checkerwork by being directed through it from top to bottom. The temperature of the checkerwork at the top, i.e. the dome temperature, can be about 1400°C. The temperature of the hot flue gases decreases on its way down towards the bottom of the checkerwork. The bottom of the checkerwork rests on a support assembly, which usually comprises a support grid mainly composed of cast iron grates placed on cast iron beams, which are resting on top of some vertical cast iron columns called support columns. A cavity is thus obtained under the checkerwork. In conventional stoves, the height of this cavity is usually about 2 to 4 meters. Although conventional support assemblies have shown a long service life in the stove, they are limited in the temperature they can withstand. Indeed, the maximum temperature of the hot flue gases at the location of such a support assembly is limited by the thermal strength of the cast iron and is usually limited to about 400°C.

[0006] When this maximum temperature of the hot flue gases is reached at the location of the support assembly, the combustion is stopped and thus the flow of flue gases. In other words, the heat stored in the checkerwork is limited to the maximum temperature that the support assembly can withstand.

[0007] At this point, the hot blast stove is placed in the "blowing phase". At this point, cold air is introduced into the hot blast stove through the cavity below the checkerwork and is directed upwards through the hot checkerwork. When the cold air passes through the checkerwork, heat is transferred from the checker bricks to the cold air, which is thereby turned into hot air. The hot air is then supplied to the blast furnace. There is also a certain amount of cold air that bypasses the stove (hot blast stove) and is introduced into the hot air through a mixing valve before entering the blast furnace to ensure a constant hot air temperature before being introduced into the blast furnace. When the outlet temperature of the hot air decreases below a temperature threshold (typically about 1250°C), the control switches to another stove (hot blast stove). Then, the hot blast stove is again placed in the "combustion phase". During normal operation of the blast furnace, three stoves (hot blast stoves) are used, so that at all times at least one stove is in the "blowing phase". It is noted, however, that depending on the layout of the production plant and the type and design of the hot blast stoves, the number of stoves can also be more or less than three. For example, it is not uncommon for two or four hot blast stoves to be used per blast furnace or for five hot blast stoves to be used per two blast furnaces.

[0008] In an integrated steel plant, the hot blast stoves account for 10 to 15% of the total energy demand. It is known that the efficiency of the hot blast stove system can be improved by increasing the maximum temperature of the hot flue gases, which is currently about 400°C.

[0009] US patent application US 2008199820 A1 discloses the use of a support assembly comprising a support grid and support columns made of metal, for example a special cast iron material comprising a ferritic matrix and a dispersion of vermicular or spheroidal graphite particles. The use of the generic metal and this special cast iron allows the use of hot flue gases with a maximum temperature of up to about 600°C. However, the cast iron is nitrided by the ammonia contained in the blast furnace gases (used as a combustible gas) - which reduces the service life of the support assembly in the stove - when the temperature of this combustible gas is higher than 500°C. SUMMARY

[0010] OBJECTIVE

[0011] It is an object of the present invention to provide a heat storage device, for example a hot blast stove, comprising an improved support assembly for supporting a heat regeneration checkerwork, which is able to withstand higher temperatures and temperature fluctuations of hot gases and chemical attack from these gases, while ensuring as uniform as possible a distribution of the gases in the hot blast stove. SUMMARY

[0013] The present invention proposes a heat storage device, in particular a hot blast stove, comprising a support assembly and a regenerative checker body made of checker bricks, which is supported by the support assembly. According to an aspect of the invention, the support assembly comprises a load bearing structure made of a refractory material and load bearing slabs also made of a refractory material, which are arranged on the load bearing structure and are configured and shaped to carry the checker bricks of the checker body.

[0014] The use of refractory material only, even at temperatures of up to about 900°C, prevents the support assembly from deteriorating and provides the support assembly with a higher resistance to nitriding or stress corrosion cracking. Thus, since the support assembly according to the invention does not comprise any metallic support or load bearing (structure) elements, such as cast iron parts, it can withstand higher temperatures than conventional support assemblies, and the hot blast stove according to the invention can heat air to a higher temperature than conventional hot blast stoves. The expression "made of a refractory material" generally refers to load bearing (carrier) structures and / or load bearing (carrier) slabs which essentially consist of a refractory material, such as a ceramic refractory material. In other words, the load bearing structure and / or the load bearing slabs are preferably formed of refractory material only.

[0015] Since the support assembly can withstand higher temperatures, the heat storage device can be used to heat other gases than air; it can for example be used to heat synthesis gas. For simplicity, the present application generally discusses the heating of air. However, it should be noted that other gases can also be heated. Thus, the term "air" can be replaced by "gas" herein.

[0016] Advantageously, the refractory material used for the support assembly is a ceramic refractory material. Preferably, the refractory material is the same as the material used for the lower part of the checker body, such as high alumina, but is not limited thereto. The use of a single material type is beneficial since it reduces the risk of failure of the support assembly - in case the checker body does not fail.

[0017] The load bearing slabs can advantageously be configured and shaped to extend, preferably gradually extend, the upper surface area of the load bearing structure to cover the entire surface area of the checker body. By (gradually) extending the upper surface area (upper surface area) of the load bearing structure, the surface area available for supporting the checker body (gradually) increases, that is, the projected area of the support assembly (gradually) increases.

[0018] It should be noted that the term "extension" should be understood in the broadest possible way. The extension of the upper surface area of the load bearing floor of the load bearing structure can simply mean that the possible larger holes inherent to the formation of the load bearing structure are reduced or covered by the load bearing floor, and should of course not be limited to the embodiment where the load bearing structure does not cover the entire bottom portion of the hot blast stove.

[0019] According to an embodiment of the present application, the support structure can comprise a plurality of support columns made of refractory material. In order to ensure the passage of the gas flow through most of the passages of the checker bricks forming the checker body, the support columns can be hollow columns, preferably having at least one through opening along their radial direction for the passage of the gas flow. In some embodiments, the at least one opening can be a circular opening or an oblong (rectangular / elliptical) opening, the skilled person will know how to adapt the position, size and aspect ratio of the opening to ensure sufficient stability of the support column.

[0020] The inner diameter of the hollow support columns preferably corresponds to 25% to 75% of the outer diameter of these support columns, more preferably to a ratio of 40% to 60%, even more preferably the inner diameter is half of the outer diameter.

[0021] The support columns are evenly distributed over the floor of the hot blast stove to ensure a distribution of the gas flow as uniform as possible. Advantageously, and in order to ensure a compromise between the stability requirements of the support assembly (for example by using larger columns) and sufficient / adequate gas flow and gas distribution, the support columns are arranged to cover 5% to 40% of the floor of the hot blast stove, more advantageously between 15% and 30%, even more preferably between 20% and 25%.

[0022] According to another embodiment of the present application, the support structure can comprise a plurality of support arches (arches) made of refractory material. Each arch can be formed of a plurality of arch segments, preferably designed in an assembled form, which will result in a joint area along the radial cross section of the overall arch. Each support arch can be arranged radially with respect to the central axis of the heat storage device, or parallel to the central axis of the heat storage device.

[0023] According to another embodiment of the present application, the support structure can comprise a plurality of support walls made of refractory material, preferably ceramic refractory material. These walls can be arranged in parallel, but also in a cross or hexagonal arrangement. The support structure can further comprise a plurality of transition bricks designed to extend advantageously between at least two support walls. According to an embodiment, the transition bricks can form the load bearing floor. Alternatively, the transition bricks can carry the load bearing floor. In either way, the transition bricks will thus (directly or indirectly) support the checker bricks above, while improving the gas flow distribution in all passages of the checker bricks forming the checker body.

[0024] Advantageously, in these embodiments where support walls are used, the carrier deck comprises carrier bricks, which can be identical to the bricks forming the checkerwork, so that the checkerwork resting on the carrier deck can appear to be resting directly on the support walls. In other words, in these embodiments, the carrier deck is formed by the checker bricks of the checkerwork. Alternatively, the carrier bricks can also be similar to the transition bricks of the support structure.

[0025] In embodiments where the support walls are arranged in a parallel or cross configuration, it can be advantageous to use rectangular or square bricks as transition bricks of the carrier structure and / or to form the carrier deck.

[0026] It is noted that the various embodiments described above can be combined, so that the carrier structure can comprise a plurality of support columns and a plurality of support arches, or a plurality of support arches and a plurality of support walls, or a plurality of support walls and a plurality of support columns, or a plurality of support columns, a plurality of support arches and a plurality of support walls.

[0027] In order to achieve a uniform distribution of the heat carrier medium, i.e. in order to achieve a uniform gas distribution, an annular channel can be provided around the support assembly.

[0028] The annular channel is preferably defined on the outside by a steel cylinder, which is protected by a refractory wall, i.e. insulated, for example forming a hot blast stove. The refractory wall can carry the cylindrical shaft wall of the hot blast stove. Furthermore, the annular channel is preferably defined on the inside by the support assembly itself, for example by the carrier structure, or by a perforated cylindrical wall resting on the hot blast stove deck. Such a perforated cylindrical wall can also advantageously carry the shaft brickwork above.

[0029] The annular channel can be provided in an enlarged lower section of the steel cylinder, or integrated into the steel cylinder, in which section the checkerwork diameter can need to be reduced depending on the height of the annular channel. In such embodiments, the checkerwork can expand above the annular channel in order to cover the entire inner diameter of the hot blast stove.

[0030] It should be noted that the distribution of the gas is not limited to a concentric annular channel around the support assembly. It can also be distributed by one or more arches located between two adjacent support walls of a row of support walls.

[0031] According to various embodiments of the invention, the carrier deck can comprise at least one of the following two layers, or a combination of the two layers:

[0032] - a layer described as a widening structure, which can comprise widening blocks;

[0033] - one layer comprising distribution blocks and described as distribution layer.

[0034] In the context of the present invention, the two expressions "widening structure" and "distribution layer" are thus understood to mean the said load-bearing layer.

[0035] According to a first preferred embodiment, the load-bearing layer acts as a widening structure and comprises a plurality of rows of checker bricks. Successively consecutive rows of checker bricks are arranged in a staggered configuration so as to gradually expand the area of the upper surface of the support column to cover the entire surface area of the checker body.

[0036] This staggered configuration of checker bricks can be inspired from roman brickwork. In a preferred embodiment, the checker bricks have the shape of a hexagonal prism and the first row of checker bricks is made so that between 1 and 12 checker bricks are placed on each support column, preferably 6 checker bricks are placed on each support column. Advantageously, each checker brick of the first row is contiguous to at least two other checker bricks of the same row. The checker brick(s) can contact two adjacent bricks with at least two consecutive sides, forming as compact an assembly as possible, preferably forming a triangular shape. The checker brick(s) forming the upper row(s) of the widening structure can be arranged so that each row maintains a substantially triangular shape above each support column while expanding the surface area of the triangular shape at each row.

[0037] Alternatively, the checker brick(s) can contact two adjacent bricks with two non- consecutive sides, forming an assembly with a hexagonal shape. The checker brick(s) forming the upper row(s) of the widening structure can be arranged so that each row maintains a substantially hexagonal shape above each support column while expanding the surface area of the hexagonal shape at each row.

[0038] Advantageously, the checker bricks arranged in a staggered configuration to form the load-bearing layer considered as a widening structure are conventional checker bricks, more preferably the said checker bricks are identical to those used for the checker body. The existing checker bricks can be reused to avoid unnecessary production costs or to avoid manufacturing complex refractory shapes.

[0039] Alternatively, special bricks can also be designed to form the load-bearing floor. According to a second preferred embodiment, the load-bearing floor comprises at least one widened block having two parallel surfaces and at least three other surfaces, typically six other surfaces. The at least three other surfaces are referred to as side surfaces. The first parallel surface of the widened block defines (delimits) a lower surface intended / configured to rest on the load-bearing structure, preferably on a support column; while the second parallel surface of the widened block defines (delimits) an upper surface intended / configured to support the lattice. In other words, the first parallel surface of the widened block defines a lower surface resting on the load-bearing structure, and the second parallel surface of the widened block defines an upper surface supporting the lattice.

[0040] The expression "intended to support the lattice" or "configured to support the lattice" must be understood in a broad manner, the lattice being placed on the widened block, without being limited to a position in direct contact with the widened block.

[0041] The widened block according to the application can have the form of a hexagonal prism or a hexagonal frustum.

[0042] The widened block having the form of a hexagonal prism can be said to be a large block, a large hexagonal lattice brick, or simply a larger lattice brick. This shape of the widened block is easy to manufacture and install. It is possible to extend the area of the upper surface of the support column downwards to the inner wall of the hot stove more easily.

[0043] In the embodiment in which the widened block has the form of a hexagonal frustum, the smaller of the two parallel surfaces is considered to be the lower surface, the widened block can be described as presenting an elephant foot shape.

[0044] The widened block, whatever its shape, acts as an intermediary between the load of the lattice (directly or indirectly pushed down on it) and the support column (on which it rests), increasing the area of the support surface of the column, thus enabling a better distribution of the constraints within the load-bearing floor.

[0045] Advantageously, the widening block comprises at least one internal passage which is centrally located with respect to the upper surface of the block. In embodiments in which the widening block comprises more than one internal passage, the passages are preferably arranged in a regular pattern, i.e. a repeating pattern, with their outlets located on the upper surface of the widening block. The term "regular pattern" can thus generally refer to an arrangement of the passages which presents an ordered or stable arrangement with respect to each other. In order to ensure a more homogeneous flow of gas within the entire structure of the hot stove, the passages of the widening block preferably have the same diameter as the passages of the checker bricks (or conventional checker bricks) and their outlets are advantageously positioned in alignment therewith. The internal passages can be straight and perpendicular to the upper parallel surface of the widening block. Alternatively, they can be curved, having an outlet on the upper surface of the widening block and an inlet on one of the at least three lateral surfaces. This second embodiment can be particularly advantageous if the support pillars are solid (i.e. not hollow), in order to ensure a distribution of gas in the passages of the checker bricks (which form a checker body, placed in line above the support pillars). Thanks to these passages which ensure a distribution of gas in the passages of the checker bricks, the widening blocks can act as distribution blocks, even if their main function is to gradually expand the area of the upper surface of the support pillars to cover the entire surface area of the checker body.

[0046] Advantageously, when the bearing structure comprises a plurality of hollow pillars, the cross-section of the central passage of the widening block on its lower surface corresponds to the internal cross-section of the support pillars. The cross-section of the central passage can then widen (enlarge) in the direction towards the upper surface of the widening block. This central passage enables a more homogeneous distribution of the gas flow through the passages of the checker bricks placed above the widening block.

[0047] In other embodiments, each of the at least three side surfaces of the widening block comprises at least one recess. Advantageously, the at least one recess is a circular recess. Preferably, when the widening block comprises at least one internal passage, the radius of curvature (or diameter) of the at least one recess is equal to the radius of curvature (or diameter) of the at least one internal passage. According to some embodiments, the central passage can have a larger diameter than the other internal passages of the widening block. When this occurs, the radius of curvature (or diameter) of the at least one recess can be equal to the radius of curvature (or diameter) of the smaller internal passage. In other words, the recess formed on the side surface of the widening block has a size equal to or at least close to the size of the internal passage formed through the widening block. When two widening blocks are placed next to each other, the at least one recess of one block will preferably face the at least one recess of the other block so as to form at least one additional passage that enhances the air flow distribution through the load bearing panel. In other words, the recess is formed and dimensioned so that, when two blocks are placed next to each other, a new additional passage is formed between the two adjacent blocks.

[0048] The widening blocks can be formed of a plurality of block segments, preferably designed in an assembly form, which will result in joint areas along the radial or longitudinal cross section of the overall widening block.

[0049] The widening blocks are preferably dimensioned so that a single row of widening blocks extends the upper surface area of the support column to cover the entire surface area of the lattice. In some embodiments, the widening blocks have the shape of a hexagonal prism, i.e. the widening blocks are larger lattice tiles, and the load bearing panel can comprise a plurality of rows of widening blocks arranged in a quincunx pattern to increase the stability of the structure.

[0050] Alternatively, the widening blocks can be dimensioned so that a single row of widening blocks extends the upper surface area of the support column to partially cover the surface area of the lattice. According to this embodiment, the load bearing panel further comprises one or more rows of lattice tiles to cover the entire surface area of the lattice.

[0051] In other embodiments, the load bearing panel comprises a plurality of distribution blocks having at least three side surfaces, typically four or six side surfaces. These distribution blocks form a distribution panel and the load bearing panel can be referred to as a distribution panel. The distribution panel distributes the air flow between the passages of the lattice tiles forming the lattice to enhance the uniformity of the air flow.

[0052] The distribution blocks can have two different purposes. Advantageously, they are used to simply feed the air to the internal passages of the lattice tiles placed thereon. Alternatively or additionally, they are used to ensure a smoother air flow through the internal passages of the lattice tiles placed thereon.

[0053] The distribution blocks can be arches with four lateral surfaces, or they can have the form of a hexagonal prism, with two parallel surfaces and six lateral surfaces perpendicular to the parallel surfaces.

[0054] Advantageously, the distribution blocks, whatever their shape, comprise at least one internal channel embedded within them, and the at least three lateral surfaces comprise at least one circular recess, the radius of curvature of the at least one recess presenting a radius of curvature equal to that of the at least one internal channel. When two distribution blocks are placed against each other, the at least one recess of one distribution block will advantageously face the at least one recess of the other distribution block, so as to form at least one additional channel, enhancing the distribution of the gas flow through the support slab. Advantageously, the distribution blocks are positioned next to each other so as to form a plurality of additional channels and a continuous distribution slab.

[0055] In some embodiments, the distribution blocks, which have the form of a hexagonal prism, can further comprise at least one distribution chamber forming an opening on the lower surface of the distribution block, the at least one distribution chamber preferably having the form of a hemisphere. The at least one distribution chamber ensures the flow of gas through a large part of the channels of the checker bricks, which constitute the checkerwork placed above (directly or not directly) the distribution blocks. In some embodiments in which the support structure consists of hollow support columns, the opening formed by the at least one distribution chamber on the lower surface of the distribution block has the same size as the internal diameter of the support columns and is aligned so as to facilitate the flow of gas.

[0056] Alternatively, the at least one distribution block forming the distribution slab (or support slab) can have the form of an arch.

[0057] The distribution blocks according to the application can be placed directly on the support columns, support walls or support arches. Alternatively, the distribution blocks can be positioned on a widening block. Each of the at least one distribution blocks can be placed on a widening block, or arranged between two widening blocks.

[0058] In other words, the distribution slabs can advantageously be used with all types of support structure, whether support columns, support arches or support walls. These slabs can consist of rectangular, polygonal or arched bricks, comprising circular channels, oblong holes or spherical cavities.

[0059] According to another preferred embodiment, the load floor comprises at least three rows of checker bricks which are placed directly on top of the support columns or on top of the widening blocks. These checker bricks are arranged to form a distribution chamber above the support columns between the second and the penultimate row of checker bricks which are part of the load floor. This arrangement of checker bricks enables a more uniform distribution of the gas flow through the channels of the checker bricks forming the checker body, which otherwise, especially in the area above the support columns, can be obstructed by the support columns themselves at the entrance of one or more channels.

[0060] According to another aspect, the present invention proposes a method for producing hot blast air or hot synthesis gas using a hot blast stove as a regenerative heat exchanger, i.e. heating cold blast air or cold synthesis gas, which hot blast stove comprises a support assembly as described above for supporting a regenerative checker body made of checker bricks, which is operated in a two-stage cycle with alternating "on air" and "on gas" phases, as further explained in the background section above. During operation, blast air or synthesis gas can be introduced into the hot blast stove, whereby heat is transferred from the checker body to the blast air or synthesis gas. The advantages and further embodiments outlined with respect to the (hot) blast stove apply analogously to the method as well. BRIEF DESCRIPTION OF DRAWINGS

[0061] Further details and advantages of the present invention will become apparent from the following detailed description of non-limiting embodiments with reference to the drawings, in which:

[0062] Figure 1 is a schematic view of a hot blast stove for implementing an embodiment of the support assembly of the present invention;

[0063] Figure 2 is a schematic view of a first preferred embodiment of the support assembly of the present invention;

[0064] Figure 3 is a schematic view of a distribution chamber of the support assembly according to the first preferred embodiment;

[0065] Figure 4A is a schematic view of a first variant of the arrangement of checker bricks on top of the support columns according to the first preferred embodiment of the support assembly of the present invention;

[0066] Figure 4B is a schematic view of a second variant of the arrangement of checker bricks on top of the support columns according to the first preferred embodiment of the support assembly of the present invention;

[0067] Figure 5 is a schematic view of a second preferred embodiment of the support assembly of the present invention;

[0068] Figure 6 is a schematic cross-sectional view of a first preferred embodiment of a widening block according to the present invention;

[0069] Figure 7 is a schematic cross-sectional view of a second preferred embodiment of a widening block according to the present application;

[0070] Figure 8 is a schematic view of a third preferred embodiment of a support assembly according to the present application;

[0071] Figure 9 is a schematic view of a fourth preferred embodiment of a support assembly according to the present application;

[0072] Figure 10 is a schematic view of a fifth preferred embodiment of a support assembly according to the present application;

[0073] Figure 11 is a schematic view of a sixth preferred embodiment of a support assembly according to the present application;

[0074] Figure 12 is a detailed view of Figure 11 the sixth preferred embodiment of a support assembly according to the present application;

[0075] Figure 13 is a schematic view of a seventh preferred embodiment of a support assembly according to the present application;

[0076] Figure 14 is a detailed view of Figure 13 the seventh embodiment along the x-y plane;

[0077] Figure 15 is a detailed view of Figure 13 the seventh embodiment along the x-z plane; and

[0078] Figure 16 is a detailed view of Figure 13 the seventh embodiment along the y-z plane; DETAILED DESCRIPTION

[0079] As shown in Fig. 1, the hot blast stove 10 comprises a heat exchange section, which comprises a refractory checker brick 12 assembly, called checker body 14, and a support assembly 16, on top of which the checker body 14 is arranged. Figure 1

[0080] A detailed view of the support assembly 16 according to the first embodiment of the present application is shown in Fig. 4. The support assembly 16 is entirely made of refractory material and comprises a load bearing structure 20 and a load bearing deck arranged on top of the load bearing structure 20. According to Figure 2 - the present embodiment shown in Fig. 4, the load bearing deck is a widening structure 30. The load bearing structure 20 comprises a plurality of support columns 20a. The widening structure 30 is arranged and formed to gradually expand the upper surface area 26 of the support structure 20 to cover the entire surface area of the checker body 14. Figure 2 ​

[0081] The support columns 20a have the shape of a hollow cylinder with an internal passage 24 formed therein. In two particularly preferred embodiments, the diameter of the internal passage 24 of the column corresponds to 44% or 50% of the external diameter of the hollow cylinder. The support columns 20a also have a through hole 22 in their radial direction for the passage of gas. It enables the circulation of the gas within the internal passage 24 of the column and the distribution within the passages 32 of the checker bricks 12 forming the checker 14 placed above the upper surface of the support columns 20a.

[0082] In a first preferred embodiment, as shown in Figures 2-3 Twenty-two support columns 20a with an internal diameter of 220 mm and an external diameter of 500 mm are uniformly arranged on the floor of the hot blast stove 10. Each support column also has a circular through hole 22 positioned so as not to weaken the support assembly. In the example shown, the widening structure (i.e. the load-bearing slab) 30 is composed of eight rows 34.1 to 34.8 of conventional checker bricks, that is to say, the checker bricks forming the widening structure are of the same type as the checker bricks forming the checker. In other words, in this preferred embodiment, only one type of brick is used. The number of checker bricks per row 34.i and the percentage of the surface coverage of the checker in Table 1 are shown, and the person skilled in the art will know how to adapt these values to any hot blast stove.

[0083] Row Number of tiles Surface coverage of the lattice 1 132 15％ 2 264 31％ 3 396 46％ 4 516 61％ 5 624 73％ 6 743 87％ 7 821 96％ 8 851 100％

[0084] Table 1

[0085] The checker bricks 12 forming the first row are uniformly distributed on the top of each support column so that six checker bricks 12 are placed on the top of each support column. As shown in Figure 4A the six checker bricks 12 are positioned so as to form a hollow hexagonal prism, each brick being in contact with the adjacent bricks by two non-adjacent sides. The checker bricks 12 forming the upper rows are positioned according to the same layout pattern so that the upper surface area 26 of the load-bearing structure is progressively expanded to cover the entire surface area of the checker 14. In addition, the checker bricks 12 are positioned so as to form a gas distribution chamber above the support columns 20a, which extends between the third row 34.3 and the seventh row 34.7. The purpose of this chamber is to redistribute the gas into the passages covered by the columns, in particular into the passages that are completely blocked, such as the passages 32.

[0086] Alternatively, in another variant of the first preferred embodiment, thirty-one support columns 20a with an internal diameter of 200 mm and an external diameter of 400 mm are uniformly arranged on the floor of the hot blast stove 10. Each support column also has a through hole 22 positioned so as not to weaken the support assembly, and the widening structure 30 is composed of rows 34.i of conventional checker bricks. The first row 34.1 is formed of 186 checker bricks positioned so that six checker bricks are placed on the top of each support column. As shown inFigure 4B As shown, the six checker bricks 12 are arranged so as to form a generally triangular shape. The checker bricks of the second row 34.2 are arranged on top of the checker bricks of the first row 34.1 so as to expand the surface coverage of the checker bricks of the first row 34.1 while maintaining the generally triangular shape of the checker brick arrangement above the support columns. The checker bricks forming the upper rows are arranged according to the same pattern until the surface coverage of the uppermost row corresponds to 100% of the surface area of the checker body. Furthermore, the checker bricks 12 are arranged so as to form a gas distribution chamber 40 above the support columns 20a, which extends between the fourth row 34.4 and the fifth row 34.5 and has a maximum width corresponding to the outer diameter of the support columns.

[0087] Figure 5 A detailed view of the support assembly 16 according to a second embodiment of the present application is shown. In this embodiment, thirty-five support columns 20a having an inner diameter of 250 mm and an outer diameter of 500 mm are arranged uniformly on the ground of the hot stove 10. Each support column also has a through hole 22 positioned so as not to weaken the support assembly and the widening structure 30 is composed of widening block(s) 50.

[0088] As shown in Figure 6 or Figure 7 The widening blocks 50 can have the form of a hexagonal prism with two parallel surfaces 56-58 and internal channels 52 arranged in a regular pattern. The internal channels can be straight Figure 6 or curved Figure 7 with respect to the upper one of the two parallel surfaces. The widening blocks are seated on top of the support columns 20a by their smaller and lower (lower) parallel surface 56, while the upper and larger parallel surface 58 is configured to support the checker body 14. The widening blocks 50 are dimensioned so that a single row of widening blocks expands the upper surface area 26 of the load bearing structure to cover the entire surface area of the checker body 14. In order to ensure a smoother gas flow throughout the structure of the hot stove 10, the internal channels 52 of the widening blocks 50 preferably have the same diameter as the channels 32 of the regular checker bricks 12 forming the checker body 14, and their outlets are positioned on the upper surface 58 so as to be aligned therewith. The widening blocks 50 also comprise a central channel 54 having a cross section on the lower surface 56 corresponding to the diameter of the internal channels 22 of the support columns and a larger cross section on the upper surface 58.

[0089] The skilled person can use other possible embodiments of the widening blocks 50. In particular, the widening blocks 50 can have only one internal channel, preferably as a central channel 54, as shown in Figure 8The central channel has the same diameter as the internal channel 24 of the support column to ensure a smooth flow of gas for the penetration of the gas through the lateral slit holes 22 of the support column 20. The lateral surface of the hexagonal prism has circular grooves with a radius of curvature (or diameter) equal to the radius of curvature (or diameter) of the central channel. If the dimensions of the widening blocks 50 are designed so that a single row of widening blocks is sufficient to cover the entire surface of the upper grid 14 (as shown in the embodiment of Figure 8 or Figure 9 ), each widening block will be in contact with the other. The circular grooves on one lateral surface of a first widening block will thus face the circular grooves on one lateral surface of a second widening block. These two grooves will define, when assembled, a channel, called a contact channel 66, because it is formed by the contact of two blocks. The contact channel 66 actively participates in the uniform distribution of the flow of gas in the channels of the grid placed above, which are part of the load-bearing floor or grid. Widening blocks 50 placed next to each other form a single floor, the flatness of which is easier to adjust than that of the columns separated from each other.

[0090] In addition, distribution blocks 62 can be placed on top of the widening blocks 50 to form a distribution floor 60. This distribution floor is considered as part of the load-bearing floor, just as the widening structure is formed by the widening blocks. The widening structure 30 and the distribution floor 60 should each be considered as a layer of the load-bearing floor.

[0091] The distribution blocks 62 can be hexagonal prisms (as in Figure 8 ) or arches (as in Figure 9 ) made of refractory material. The main purpose of the distribution blocks is to ensure a smoother and more uniform flow of gas throughout the structure of the hot stove 10, and therefore the distribution blocks 62 can be called smoothing distribution blocks 62a. In the particular embodiment of Figure 8 and Figure 9 , the distribution blocks 62a have an internal channel 64. In the preferred embodiment, the channel 64 of the distribution blocks 62a is curved, thus ensuring the distribution of the gas to all the channels of the grid placed on top of it. The lateral surface of the distribution blocks 62a has regularly arranged circular grooves, so that when two distribution blocks are positioned next to each other, new and additional distribution channels are formed for the flow of gas. These channels between two distribution blocks can be described as contact channels 66', because they are formed by two distribution blocks next to each other.

[0092] As an alternative to Figure 9 , the load-bearing structure 20 can comprise a plurality of arches 20b instead of hollow columns 20a. The arches can be described as support arches. In this preferred embodiment, the distribution floor 60 is positioned directly above the support arches (see Figure 10). The dimensions of the distribution blocks 62a are designed to spread out the distribution between the two support arches, thus expanding the upper surface area 26 of the load bearing structure.

[0093] As Figure 11 illustrated, this is another preferred embodiment of a support assembly according to the present application. The support columns 20a are hollow columns, with through holes 22 for the passage of gas, but they can also be solid columns, i.e. not hollow. The widening blocks 50 are positioned on the support columns 20a, but the blocks do not touch each other, so that gas can flow between them. In this particular embodiment, the widening blocks 50 are solid, i.e. they do not have any channels. It is therefore necessary to ensure the distribution of the gas through the internal channels 32 of the checker bricks placed above the widening blocks, so that feeding distribution blocks 62b are used. The main objective is to feed the channels 32 with gas, and these feeding distribution blocks 62 can be considered as feeding distribution blocks 62b. They are placed on the widening blocks 50 along the edges of the blocks, thus leaving an unoccupied surface above the centre of each widening block 50, and have the form of an arch. This particular way of arranging the distribution blocks 62b, combined with their shape, ensures that the gas will flow through the arch towards the free area, and will then be distributed into the internal channels of the checker bricks arranged above the widening blocks 50. Thus, the arrangement of the distribution blocks on top of the widening blocks allows the use of solid columns, which are easier to manufacture, and less complex widening blocks 50, and improves the solidity of the support assembly 16.

[0094] Figure 11 The load bearing deck in the example illustrated comprises, in addition to the widening structures 30 made of widening blocks 32 and the distribution deck made of distribution blocks 62, four rows 34.1 of checker bricks 12 positioned in an interlaced manner to gradually expand the upper surface of the distribution blocks, and thus of the support columns 20a, to cover the surface corresponding to the entire surface of the checker body 14. The rows 34.1 to 34.4 of checker bricks 12 are arranged to form a distribution chamber 40 Figure 12 above the support columns 20a, to further optimize the distribution of the gas flow in the channels of the checker bricks forming the checker body 14.

[0095] Yet another preferred embodiment of a support assembly according to the present application is presented in Figures 13 to 16 . The load bearing structure comprises a plurality of support walls 20c arranged next to each other to form a plurality of rows. These rows are parallel to each other and can be connected by, for example, connecting columns 72 to enhance the stability of the load bearing structure. The connecting columns can be replaced by rectangular connecting bricks (not illustrated). The load bearing structure can comprise a plurality of such rows arranged in a rectangular (as illustrated in Figure 13 ) or hexagonal manner, thus forming a grid of support walls. The load bearing structure further comprises a plurality of transition bricks 70, which can be arranged among the plurality of layers, for exampleFigure 13 In the two layers shown, the bottommost transition brick 70 is arranged to span between two or more parallel support walls 20c. The transition brick 70 may be provided to reinforce the load-bearing layer supporting the lattice 14.

[0096] exist Figures 13 to 16 In this embodiment, the support layer is made of a plurality of bricks 74. The bricks 74 of the support layer may have a cross-section that tapers toward the checker bricks and grooves on their outer surfaces to ensure and / or improve airflow distribution in the channels of the checker bricks forming the checker body.

[0097] The supporting wall 20c and / or transition brick 70 can be the same as or similar to the burner bricks and supporting structures used in metallurgical furnace burners. Existing bricks and / or walls can be reused to avoid unnecessary production costs or to avoid having to manufacture complex refractory shapes.

[0098] like Figure 15 As shown, the support wall 20c can also be combined with the arch 76 to form a load-bearing structure, which can ensure better gas distribution and / or create passageways for operators during maintenance. In some embodiments, the support arch 20b is used as the arch 76, but this is not mandatory.

[0099] The arch frame 76 can be made from multiple arch segments 78, such as Figure 16 As shown, the bricks 80 forming the support wall 20c can be positioned on top of the arch frame 76 so that the support wall 20c extends above the arch frame 76 to support the transition bricks 70 (see...). Figure 16 ).

[0100] It should be noted that the above embodiments are for illustrative purposes only. Those skilled in the art can readily modify the indicated quantities, dimensions, and shapes to adapt the support structure to the specific design and operating conditions of the corresponding furnace.

[0101] Explanation of reference numerals in the attached figures

[0102] 10: Hot air furnace

[0103] 12: Checkered bricks

[0104] 14:Grid body

[0105] 16: Support components

[0106] 20: Load-bearing structure

[0107] 20a: Support column

[0108] 20b: Supporting arch

[0109] 20c: Supporting wall

[0110] 22: Through hole

[0111] 24: interior channel

[0112] 26: upper surface area of the load bearing structure

[0113] 30: widening structure

[0114] 32: channel of the grid tile

[0115] 34.i: row of grid tiles

[0116] 40: distribution chamber

[0117] 50: widening block

[0118] 52: interior channel of the widening block

[0119] 54: central channel of the widening block

[0120] 56: lower surface

[0121] 58: upper surface

[0122] 60: distribution deck

[0123] 62: distribution block

[0124] 62a: smooth distribution block

[0125] 62b: feed distribution block

[0126] 64: interior channel of the distribution block

[0127] 66: contact channel of the widening block

[0128] 66': contact channel of the distribution block

[0129] 70: transition tile

[0130] 72: connecting column

[0131] 74: tile of the load bearing deck

[0132] 76: arch

[0133] 78: tile forming the arch

[0134] 80: tile forming the support wall

Claims

1. A heat storage device, comprising a support assembly and a heat storage grid made of checker bricks, the heat storage grid being supported by the support assembly, characterized in that, The support components include: - A load-bearing structure made of refractory material, the load-bearing structure comprising a plurality of support columns, wherein the support columns are hollow columns and have at least one through hole for gas flow along the radial direction of the support columns; - A load-bearing plate made of refractory material, which is placed on the load-bearing structure and is configured and formed to support the grid bricks of the heat storage grid; Furthermore, the support assembly does not include any metal supports or metal load-bearing elements.

2. The thermal storage device according to claim 1, wherein, The refractory material is a ceramic refractory material.

3. The thermal storage device according to claim 1, wherein, The load-bearing plate is configured and formed to extend the upper surface area of ​​the load-bearing structure to cover the entire surface area of ​​the heat storage lattice.

4. The thermal storage device according to claim 1, wherein, The at least one through hole of the support column is a circular through hole or an elongated through hole.

5. The thermal storage device according to claim 1, wherein, The load-bearing structure includes multiple supporting arches.

6. The thermal storage device according to claim 1, wherein, The load-bearing structure includes multiple support walls and multiple transition bricks, each transition brick extending between at least two support walls.

7. The thermal storage device according to any one of claims 1 to 6, wherein, The supporting layer includes multiple rows of grid bricks, which are arranged in an alternating pattern to gradually expand the upper surface area of ​​the support column and cover the entire surface area of ​​the heat storage grid.

8. The thermal storage device according to any one of claims 1 to 6, wherein, The load-bearing plate includes a widening block having two parallel surfaces and at least three other surfaces called side surfaces, wherein the first parallel surface of the widening block defines a lower surface configured for placement on the load-bearing structure, and the second parallel surface of the widening block defines an upper surface configured for supporting the heat storage lattice.

9. The thermal storage device according to claim 8, wherein, The widened block has the form of a hexagonal prism.

10. The thermal storage device according to claim 8, wherein, The widened block has the form of a hexagonal frustum, and the lower surface is the smaller of the two parallel surfaces.

11. The thermal storage device according to claim 8, wherein, The widening block includes internal channels arranged in a repeating pattern, and the outlet of the internal channels is located on the upper surface of the widening block.

12. The thermal storage device according to claim 11, wherein, The internal channel of the widened block has the same diameter as the channel of the checker brick, and its outlet is located on the upper surface of the widened block, aligned with the channel of the checker brick.

13. The thermal storage device according to claim 8, wherein, The widening block also includes a central channel having a cross-section on the lower surface corresponding to the inner cross-section of the support column.

14. The thermal storage device according to claim 13, wherein, The cross-section of the central channel of the widened block is widened in the direction toward the upper surface.

15. The thermal storage device according to claim 8, wherein, Each of the at least three side surfaces of the widened block includes at least one groove.

16. The thermal storage device according to claim 15, wherein, The widening block includes internal channels arranged in a repeating pattern, and the outlet of the internal channels is located on the upper surface of the widening block.

17. The thermal storage device according to claim 16, wherein, The at least one groove is a circular groove, and its radius of curvature is equal to the radius of curvature of the internal channel.

18. The thermal storage device according to claim 15, wherein, The widening block also includes a central channel having a cross-section on the lower surface corresponding to the inner cross-section of the support column.

19. The thermal storage device according to claim 18, wherein, The at least one groove is a circular groove, and its radius of curvature is equal to the radius of curvature of the central channel.

20. The thermal storage device according to claim 8, wherein, The widened block is formed by multiple block segments.

21. The thermal storage device according to claim 8, wherein, The size of the widening blocks is determined in such a way that a single row of widening blocks expands the upper surface area of ​​the support column to cover the entire surface area of ​​the heat storage lattice.

22. The thermal storage device according to claim 21, wherein, The load-bearing layer comprises multiple rows of widened blocks arranged in a staggered, quincunx pattern.

23. The thermal storage device according to claim 8, wherein, The size of the widening block is determined in such a way that a single row of widening blocks extends the upper surface area of ​​the support column to partially cover the surface area of ​​the heat storage grid, and the bearing plate further includes one or more rows of grid bricks to cover the entire surface area of ​​the heat storage grid.

24. The thermal storage device according to any one of claims 1 to 6, wherein, The load-bearing layer includes a plurality of distribution blocks having at least three side surfaces.

25. The thermal storage device according to claim 24, wherein, The distribution block includes at least one internal channel embedded therein, and the at least three side surfaces include at least one circular groove, the radius of curvature of the at least one groove being equal to the radius of curvature of the at least one internal channel.

26. The thermal storage device according to claim 24, wherein, Each distribution block forms the load-bearing plate and has the form of a hexagonal prism, having two parallel surfaces and six side surfaces perpendicular to the parallel surfaces.

27. The thermal storage device according to claim 26, wherein, At least one of the distribution blocks further includes at least one distribution chamber, the distribution chamber forming an opening on one of the two parallel surfaces of the distribution block.

28. The thermal storage device according to claim 27, wherein, The opening formed by the at least one distribution chamber on one of the two parallel surfaces of the distribution block is the same as and aligned with the inner diameter of the support column.

29. The thermal storage device according to claim 24, wherein, Each distribution block forms a distribution layer, and the distribution block is an arch frame.

30. The thermal storage device according to claim 24, wherein, The load-bearing plate includes a widening block, and the distribution block is placed on the widening block.

31. The thermal storage device according to any one of claims 1-6, wherein, The load-bearing layer includes at least four rows of grid bricks, which are arranged above the load-bearing structure to form distribution chambers, which are located between the second row and the penultimate row of grid bricks in the load-bearing layer.

32. A method for heating blower air using a heat storage device according to any one of claims 1 to 31 as a regenerative heat exchanger.

33. A method for heating syngas using a heat storage device according to any one of claims 1 to 31 as a regenerative heat exchanger.

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